Nowadays, flat display devices are being extensively developed. Among them, liquid crystal display devices are mounted on various electronic apparatuses, since they have such advantages as being lightweight, thin, and consuming little energy. As a method of controlling a liquid crystal alignment state, presented are display devices using a method of controlling the alignment state of liquid crystal with a vertical electric field such as twisted nematic (TN) mode and optically compensated bend (OCB) mode, and display devices using a method of controlling the alignment state of liquid crystal with a transverse electric field (including fringe electric field) such as in-plane switching (IPS) and fringe field switching (FFS) modes.
For example, resolution of display devices mounted on smartphones and tablet computers is being enhanced, and it is required to reduce the pixel size of liquid crystal display devices.